著者

波戸 謙太 金堀 哲也 谷川 聡 梶田 和宏 奈良 隆章 川村 卓

出版者

日本コーチング学会

雑誌

コーチング学研究 (ISSN:21851646)

巻号頁・発行日

vol.35, no.1, pp.1-17, 2021-10-20 (Released:2021-12-28)

参考文献数

32

---

This study delineates the common characteristics of pitching motion in professional baseball pitchers by focusing on their lower limbs. Further, to gain an insight into the development of athletic capacity, the pitching motion of the Top group was compared with the Minor group, resulting in the clarification of lower limb issues in the Minor group. Data analysis was performed using a test with the highest score in a 5-point objective evaluation by the observer and the highest ball speed in the tracking data obtained from Trackman, with the following results: (1) The common characteristics in a professional baseball pitcher was that the hip joint was flexed while the stride leg knee joint angle was fixed to MBV (Minimum Ball Velocity), MER (Maximal Shoulder External Rotation), and the stride leg hip joint and knee joint were slightly extended to MER, REL (Ball Release). (2) Regarding the difference between the Top and Minor groups, it is suggested that the Top group accelerates the rotational speed of the lower torso to SFC (Stride Foot Contacts Ground), which increases the angular velocity of adduction of the hip joint of the stride leg, resulting in torsion of the trunk and stable force transmission after MBV. (3) In the Top group after SFC, the angular displacement and angular velocity was such that the hip joints of both legs were fixed. Additionally, the stride leg hip joint was in adduction, which caused the motion to increase the rotation of the lower and upper torsos. Authors suggest considering these key points while coaching baseball.

著者

梶田 和宏 川村 卓 島田 一志 金堀 哲也 八木 快

出版者

日本コーチング学会

雑誌

コーチング学研究 (ISSN:21851646)

巻号頁・発行日

vol.32, no.2, pp.171-187, 2019-03-20 (Released:2019-09-02)

参考文献数

55

---

This study clarifies the features of throwing motion to second base of professional baseball catchers.Eleven catchers of two Nippon Professional Baseball Organization teams were participants. Using the highest confidence data among analytical trials for throwing time, we defined it as ‘the time required from catching until ball arriving at second base with shortest time’. Following five characteristic features were revealed. 1) In time parameter, professional catchers have a difference in motion time (the time required from catching to release in amateur catchers), especially during the beginning phase having a relation with duration time (arrival time from the ball release to the second base), the throwing phase having a relation with the throwing time and release speed (speed average of ball speed of 3 frames after releasing the ball), and the grip changing phase having a relation with motion time. 2) Further, professional catchers have a tradeoff relationship between the motion time and the duration time as well as amateur catchers; and, particularly good professional catchers can shorten the duration time even while shortening motion time leading to shortening of the throwing time. 3) In stride parameter, professional catchers have a difference in the length of the pivot foot in amateur catchers, especially, the X component has a relation with the motion time while the Y component has a relation with the duration time, and the stride length is likewise; there was no relationship between all the items. 4) In release parameter, professional catchers maintain a higher projection height of the ball than amateur catchers and maintain the tendency of the projection angle to be lower, improving the throwing accuracy, especially the elevation angle is related to the duration time and the release speed, but the azimuth angle is likewise; there was no relationship between all the items. 5) In center of gravity of the body, professional catchers have a relation with the movement speed of the center of gravity of the body and the release speed as well as amateur catchers, but the moving distance of center of gravity of the body is likewise; there was no relationship between all the items.

著者

青山 敏之 阿江 数通 相馬 寛人 宮田 一弘 梶田 和宏 奈良 隆章 川村 卓

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.70, no.1, pp.91-100, 2021-02-01 (Released:2021-01-13)

参考文献数

44

被引用文献数

3 2

---

The yips represent a disorder that makes it challenging for an individual to perform automatic and coordinated movements in sports activities. The cause of the yips is not sufficiently clarified, and limited information is available regarding throwing yips in baseball. Therefore, this study was designed to clarify the incidence and characteristics of the throwing yips among college baseball players. Total 107 players of the college baseball team participated in the study and completed the questionnaire by answering questions about their experience of the yips (loss of control to throw the ball accurately for more than 1 month), the symptom intensity, and changes observed in the symptoms in different situations. The 47.1% of players met the definition of throwing yips. The symptoms of the yips were more pronounced with short-distances and low intensity of throwing. Moreover, there were various subjective symptoms, such as the issue about co-contraction of the upper limb, sensory function, body ownership, and movement planning. Various physical symptoms associated with throwing yips suggest that the yips are not only a disorder of motor skills, but result from movement disorders. The present results show that the occurrence of the yips depends on the throwing condition; this finding provides useful insights into the mechanism and the treatment of the yips. Interdisciplinary studies that aim to elucidate the cause of the yips and develop effective intervention are necessary.

著者

川戸 湧也 長谷川 悦示 木内 敦詞 梶田 和宏 中川 昭

出版者

一般社団法人 日本体育・スポーツ・健康学会

雑誌

体育学研究 (ISSN:04846710)

巻号頁・発行日

vol.65, pp.775-792, 2020 (Released:2020-11-18)

参考文献数

37

---

The purpose of this study was to design and implement judo courses of physical education (PE) in higher education (HE) based on the ADDIE model and to validate the students’ outcomes and issues. The ADDIE model is part of the Instruction Design (ID) theory of educational technology. The subjects were 162 first-year undergraduate students (91 males: 71 females) attending judo courses in a designated sports university, and the lecturer who was responsible for instruction. Courses were implemented corresponding to each of the ‘analysis’, ‘design’, ‘development’, ‘implementation’ and ‘evaluation’ phases of the ADDIE model. In the analysis phase it was confirmed that the role of the course was to provide a PE teacher’s license. Therefore, the content was designed in accordance with the course of study for junior high and high schools. Considering the lesson time (a total of 50 minutes) in junior high and high schools, the time allocation for one lesson in the course was developed with an introductory 10-minute lesson followed by a 40-minute lesson each in the first and the second half. A learning notebook (learning portfolio) was also created in order to ensure the achievement of cognitive and emotional goals, and students were asked to describe their learning during each lesson. Course implementation was by the lecturer, based on systematic observational analysis of the teaching-learning process and self-reflection. Course evaluation was conducted based on the results of the systematic observational analysis, the distribution of student grades, and self-evaluation by students. Analysis of the teaching-learning process showed that the motor learning duration was sufficiently secured while the management duration was kept low. However, visualization of the teaching-learning process revealed that the initial planned time allocation was not realized. Through these results, the importance of a systematic observational analysis can also be recognized in the PEHE. The verification of the grades distribution and the students’ self-evaluation showed that the courses had the expected outcomes as a subject related to teacher’s qualification license. Furthermore, application of the ADDIE model in this judo course highlighted some critical issues, such as increasing students’ opportunities to teach each other, adjusting the learning environment through control of temperature and hydration, and creating special teaching materials for low-skilled students. Thus, in order to guarantee and improve the quality of PEHE, the authors propose an effective approach for course design and implementation that utilizes the ADDIE model.

著者

青山 敏之 阿江 数通 相馬 寛人 宮田 一弘 梶田 和宏 奈良 隆章 川村 卓

出版者

一般社団法人日本体力医学会

雑誌

体力科学 (ISSN:0039906X)

巻号頁・発行日

vol.70, no.1, pp.91-100, 2021

被引用文献数

2

---

<p>The yips represent a disorder that makes it challenging for an individual to perform automatic and coordinated movements in sports activities. The cause of the yips is not sufficiently clarified, and limited information is available regarding throwing yips in baseball. Therefore, this study was designed to clarify the incidence and characteristics of the throwing yips among college baseball players. Total 107 players of the college baseball team participated in the study and completed the questionnaire by answering questions about their experience of the yips (loss of control to throw the ball accurately for more than 1 month), the symptom intensity, and changes observed in the symptoms in different situations. The 47.1% of players met the definition of throwing yips. The symptoms of the yips were more pronounced with short-distances and low intensity of throwing. Moreover, there were various subjective symptoms, such as the issue about co-contraction of the upper limb, sensory function, body ownership, and movement planning. Various physical symptoms associated with throwing yips suggest that the yips are not only a disorder of motor skills, but result from movement disorders. The present results show that the occurrence of the yips depends on the throwing condition; this finding provides useful insights into the mechanism and the treatment of the yips. Interdisciplinary studies that aim to elucidate the cause of the yips and develop effective intervention are necessary.</p>

著者

梶田 和宏 川村 卓 島田 一志 八木 快

出版者

一般社団法人 日本体育学会

雑誌

日本体育学会大会予稿集

巻号頁・発行日

vol.66, pp.319-320, 2015